Gaydar is the ''sixth sense'' that any gay man or lesbian woman has built into their genes that allows them to detect anyone within their immediate area who is also a ''member of the family''. Gaydar is NOT based on whether a gay man is flamboyant or whether a lesbian is masculine. Gaydar is activated and does detect other gays whether they are openly gay or not.

Maria: ''Angelo, I need you to tell me whether or not my new male friend is gay, because these days, one can never really tell.''

GAYDAR. Short for Gay-Radar. The ability to tell when someone near you is homosexual, even if they have given no obvious indications of being so. This is an ability usually possesed by homosexuals and their fag-hags.
It's like Spiderman and his Spider sense. He can just "feel" when there is danger nearby. Gaydar allows you to "feel" when there is gayness nearby.

Similar to Spidermans Spidey-sense, except where Spiderman's spidey-sense detects imminent danger, a gaydar detects a homosexual nearby, either thru hearing the tone of one's voice or observing the style of their movement, which sets off the realization that this person may prefer members of the same sex. (Being a homosexual, deal with the definition, because most should defend this one!)

and usually the ugly one's are hetero.
ie: Dick Chaney, George Bush and Bill O Reily (sad isn't it)

Kate: This guy Dave is like a total hottie!
Jeff: Dave? he's gay, my gaydar pinged when i saw him
Kate: ohh thats too bad. who else is gay?
Jeff: Your husband
Kate: Noooo you lie you fag!
Jeff: I slept with him so take that you fat bitch!